The invention relates to a reactor iron yoke clamping structure. The structure comprises silicon steel plates, a clamping plate abdomen member and an clamping plate insulating part in the electrical connection side, and another clamping plate abdomen member and another clamping plate insulating part in the insulating connection side, holes in corresponding positions of the silicon steel plates, clamping plate abdomen members and clamping plate insulating parts form at least four coaxial through holes, each through hole internally includes a clamping screw, nuts are screwed in the two ends of the clamping screw respectively, an insulating gasket is arranged between the nut, in the insulating connection side, of the clamping screw and the corresponding clamping plate abdomen member, and an insulating layer is arranged between the clamping screw and the silicon steel plates and the clamping plate abdomen members. The length of an insulting tube in the insulating connection side equals thesum of the thickness a web plate, the insulating thickness of a clamping member and the thickness of the insulating gasket. The reactor iron yoke clamping structure is simple in structure and good infastening effect, installing, positioning and insulating effects of parts as the insulating tube are taken into full consideration in design, steel gaskets can be grounded via the clamping plate abdomen member in the electrical connection side, and the using safety is fully considered.